Biphase modulator designs utilize field effect transistors (FETs) or PIN diodes as switches and are controlled at the modulation rate to give two phase conditions, 0 degrees and 180 degrees. Since both types of devices have complex impedance in the two states, matching elements are used to resonate out these parasitics. It is difficult, however, to achieve resonance in one state without effecting the resonance of the other. Consequently, the design can only approach 0 and 180 degree phase. Additional elements are often required to achieve amplitude balance, which results in increased size of the biphase modulator and insertion loss.
Next generation defense systems will be much more sophisticated and require substantially improved sensitivity. To accomplish this, it will be necessary to have a biphase modulator and method with broad bandwidth, amplitude balance, low insertion loss, and which results in a very small device. The biphase modulator and method should be cost effective. It would be desirable if a biphase modulator and method could be accomplished without the use of matching elements.